1. Field of the Invention
The present invention relates to an exhaust pressure measuring device, and more particularly, to an exhaust pressure measuring device that allows measurement of a change of pressure in an exhaust line in order to prevent problems caused by clogging of an exhaust line at a outletside of a dry pump and at an inletside of a scrubber, and an exhaust line at a outletside of the scrubber in a semiconductor or LCD apparatus in advance.
2. Description of the Related Art
Generally, a semiconductor manufacturing process includes a fabrication process and a assembly and test process. The pre-process means a process for manufacturing semiconductor chips by depositing thin films on a wafer in various process chambers and selectively etching the deposited films in a repeated way to form a predetermined pattern. The post-process means a process of individually separating the chips manufactured in the pre-process and then coupling the individual chip to a lead frame to assemble a final product.
At this time, the process of depositing thin films on a wafer or etching the films deposited on the wafer is performed at high temperature by using harmful gases such as silane, arsine, and boron chloride and process gases such as hydrogen in a process chamber. While such a process is performed, a large amount of various pyrophoric gases and byproduct gas containing harmful components and corrosive impurities are generated in the process chamber.
Thus, a semiconductor manufacturing apparatus is provided with a scrubber 15, which purifies byproduct gas discharged from a process chamber 11 and discharges the purified byproduct gas to the atmosphere, at a outletside of a vacuum pump for making the process chamber into a vacuous state, as shown in FIG. 1.
However, the harmful byproduct gas generated from the process chamber 11 is easily solidified and accumulated while flowing along an outlet-side exhaust line of the process chamber 11, an outlet-side exhaust line 14a of a dry pump 12, an outlet-side exhaust line 14b of a scrubber 13, and a main duct 15 in order, thereby resulting in clogging.
Thus, in order to prevent the clogging caused by the solidified byproduct gas, various techniques for keeping the exhaust line in a worm state have been developed. For example, a jacket heater is commonly used for entirely surrounding a certain region of an exhaust line so that the inside of the exhaust line is kept worm. Also, a method for supplying high-temperature nitrogen into an exhaust line is well known in the art.
However, although various methods have been attempted to prevent byproduct gas from being solidified and clogging the exhaust line, the byproduct gas flowing in an exhaust line is often solidified during a semiconductor manufacturing process to clog the exhaust line. This accident occurs when workers do not expect it at all, thereby causing serious damages inevitably.